Electrospinning of Highly Bi‐Oriented Flexible Piezoelectric Nanofibers for Anisotropic‐Responsive Intelligent Sensing

Abstract

AbstractFlexible piezoelectric energy harvesters (PEHs) have gained substantial attention owing to their wearability, breathability, and sustainable self‐powered supply. However, existing film PEHs cannot identify forces in different bending directions, limiting their applications in wearable electronics and artificial intelligence. This study constructs a fabric PEH for the first time by introducing piezoelectric anisotropic BaTi2O5 nanorods (BT2‐nr) into piezoelectric polyvinylidene fluoride (PVDF) nanofibers with a bi‐oriented architecture, in which BT2‐nr uniformly aligns in the PVDF nanofiber during electrospinning. The dual‐orientation feature endows the flexible PEH with anisotropy, which can sensitively identify the forces at different bending directions (e.g., bent vertically, parallelly, or twisted by 45° along the fiber orientations). Simultaneously, the composite PVDF/BT2 PEH containing 15 wt.% BT2‐nr delivers an optimal piezoelectric output of 31.2 V with a high sensitivity of 5.22 V N−1. The developed anisotropic PEH can be used as a self‐powered pressure sensor for multimodal intelligent biomonitoring of human movement. This study provides a feasible strategy for fabricating self‐powered flexible PEHs with high electromechanical conversion efficiency and multifunctionality for wearable piezoelectric pressure sensors.